Add coverage testing

pyproject.toml

@@ -6,6 +6,9 @@ test = "pytest ${PWD}"
 all = [ {ref="fmt"}, {ref="lint"}, {ref="check"}, {ref="test"} ]
 "ci:fmt" = "ruff format --check ${PWD}"  # fail if not formatted
 "ci:lint" = "ruff check ${PWD}"
+[tool.poe.tasks.coverage]
+cmd = "pytest --cov-config=${PWD}/.coveragerc --cov --cov-report=html --cov-report=term-missing"
+cwd = "${POE_PWD}"
 
 
 [project]
@@ -61,7 +64,9 @@ dev = [
     "python-dotenv>=1.0.1",
 ]
 test = [
+    "coverage>=7.8.0",
     "pytest>=8.3.5",
     "pytest-asyncio>=0.26.0",
+    "pytest-cov>=6.1.1",
     "robotframework>=7.2.2",
 ]